Urethra magnetic valve structure

ABSTRACT

A urethra magnetic valve structure comprising an implantable tubular valve housing to be located in the urethra at its juncture with the bladder. The valve housing has a pair of spaced, inflatable retention collars to be inflated for supporting the valve unit in proper position with a slotted head portion of the housing in the bladder. A valve member is resiliently biased to closed position against an apertured valve seat, and a magnetic core is connected to the valve member, to be moved by a force field generated by an electromagnet activating device external of the patient&#39;&#39;s body to open the valve and void the bladder.

ilnite States isaacson atent [1 1 1 1 URETHRA MAGNETIC VALVE STRUCTURE [76] Inventor: Leland H. lsaacson, 81 17 New Riggs {52] US. Cl 128/1 R, 128/D1G. 25, 128/349 R, 251/65 [51] Int. Cl A611! 19/00 {58] Field of Search 128/1 R, 273, 274, 349 R, 128/349 B, 350 R, DIG. 25; 251/65 [4 1 May 28', 1974 3,731,670 5/1973 Loe 128/1 R 3,750,194 8/1973 Summers 128/1 R X Primary Examiner-Dalton L. Truluck Attorney, Agent, or Firm-Mason, Fenwick & Lawrence 57 ABSTRACT A urethra magnetic valve structure comprising an implantable tubular valve housing to be located in the urethra at its juncture with the bladder. The valve housing has a pair of spaced, inflatable retention collars to be inflated for supporting the valve unit in proper position with a slotted head portion of the housing in the bladder. A valve member is resiliently biased to closed position against an apertured valve seat, and a magnetic core is connected to the valve member, to be moved by a force field generated by an electromagnet activating device external of the patients body to open the valve and void the bladder.

12 Claims, 11 Drawing Figures BACKGROUND AND OBJECTS OF THE INVENTION The present invention relates in general to an implantable control valve for controlling discharge of fluid from the urethra, and more particularly to an implantable valve device having magnetic movable parts which will respond to a magnetic field produced by an external device to control the flow of urine in patients without physical control capabilities.

Urinary incontinence is a long recognized problem in the medical field to which much effort has been directed in providing devices for handling of this problem in some way. Urinary incontinence, which is defined as the inability to control automatically or under command the elimination function of the bladder, is a widespread disorder which results from some form of neurological disfunction, usually incurable, which effects either or both the ability to sense an over capacity condition which causes involuntary forced elimination, or to control the bladder sphincters. Such incontinence may be caused by birth defects, disease, injury or aging, frequently resulting from infection in the urinary tract, and sometimes resulting after prostate removel. Waste water is discharged from the body through the urethra which leads from the bladder and is controlled by the sphincter associated with the urethra in the area of its junction with the bladder. When the sphincter becomes disabled or incapacitated, the incontinence and loss of control of the passage of waste liquids through the urethra is a circumstance which is common but quite embarrassing, awkward, uncomfortable and inconvenient.

While many methods and expedients have been employed and proposed to control and alleviate such urinary incontinence, these have possessed numerous drawbacks and disadvantages and have done little to solve this problem. The usual medical treatment has been to insert a catheter through the urethra into the bladder with an exterior water-tight collecting bag connected to the catheter tube and a flow control clamp or similar device associated with the catheter and located externally of the body. Other management techniques have included wearing of absorbent diaperlike clothing or plastic pants, but such devices present a continuing and distressing problem of odor. Also, penile clamps have been proposed, for exerting enough pressure to occlude the urethra, but extreme care must be taken in the use of such devices to prevent forces that would impair circulation or cause edema. Also, use of such a device over a long period of time may cause a urethral diverticulum at the point of pressure, and skin irritations may also develop.

An object of the present invention is the provision of an implantable magnetic valve device which serves as a semipermanent implant in the urethra to control the flow of urine by creation of a magnetic field eminating from an external device when it is desired to open the valve, and thus replace the use of catheters, urinal bags and similar devices usually employed to manage the urinary incontinence problem.

Another object of the present invention is the provision of a novel urethra valve structure of magnetic character which can be conveniently inserted in the urethra to alleviate problems of urinary incontinence,

which has inflatable retention collars to keep the device in position, and which is of such design thatit may be inserted in a convenient manner.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE FIGURES FIG. l is an elevation view of the urethra magnetic valve of the present invention, shown to approximate full scale; I

FIG. 2 is an enlarged longitudinal section view of the urethra magnetic valve, illustrating the device at a scale enlargement of about 4 to 1;

FIG. 3 is a transverse section view of the urethra valve, taken along the line 3-3 of FIG. 2;

FIG. 4 is a transverse section view through the urethra valve, taken along the line 4-4 of FIG. 2;

FIG. 5 is a transverse section view through the urethra valve, taken along the line 5-5 of FIG. 2;

FIG. 6 is an elevation view of an insertion and removing instrument for implanting and removing the valve in the urethra, with parts of the instrument broken away to reveal the interior thereof and showing adjacent portions of the urethra valve in section;

FIG. 6A is a fragmentary elevation view of the working end portion of the insertion instrument, showing the chuck or collet in collapsed condition;

FIG. 7 is a somewhat diagrammatic view illustrating the urethra valve in implanted position and illustrating the electromagnetic activator in a position of use to activate the urethra valve;

FIG. 8 is a diagrammatic view of a modified form of electromagnetic activator for the valve;

FIG. 9 is an enlarged fragmentary section view of the magnetic head portion of the activating device; and

FIG. 10 is an enlarged sectional view, similar to FIG. 2, showing a modified form of my urethra magnetic valve.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, and referring particularly to FIGS. 1 through 6, the urethra magnetic valve unit of the present invention is a small implantable device, indicated by the reference character 10, formed of an elongated, generally cylindrical housing tube ll, molded for example from a slightly flexibly deformable plastic material and having a cylindrical tubular outer wall 12 defining an elongated lower main body portion13 and a head portion 14. The head portion 14 extends over, for example, approximately one third of the axial length of the tube 11 and terminates at its upper end in a spherically configurated closed leading end or inner end 14a. The head portion 14 also is provided with a plurality of axially elongated slots or holes 14b for admitting fluid into the interior of the housing tube 11. The trailing or lower end of the main body portion 13 of the housing tube 11 is indicated at 11a, and has fixed therein a coupling ring 13a defining a constricted, upwardly converging and conically tapering throat portion 13b and an annular restraining shoulder 13c. Within the housing tube 11 in the intermediate or central zone thereof is a valve structure formed by a valve member which may be of spherical or conical configuration. The valve member 15 is normally held against a valve seat 16 by a coiled tension spring 17, secured for example to the valve member stem portion 15a extending through the valve opening 16a in the valve seat 16 and secured at its other end to an adjustment screw 18 threaded into a threaded anchor sleeve 19 at the closed end of the head portion 14. By adjusting the screw 18 and therefore the tension of the spring 17, the tension of the valve may be controlled as required to accommodate to bladder volume and pressure and to enable the valve to weep if the pressure gets too great and the bladder has not been emptied at periodic intervals, as may be necessary for paraplegics, who have no sensation.

A valve retainer member 20 is also fixed in the housing tube 11 spaced toward the lower end 11a thereof from the valve, this being a slotted collar member having slots 20a for passage of fluid and having a central opening which assists in guiding the valve member 15 by means of a connecting stem or rod 21 extending from the valve member 15 to a magnetic core member 22, for example an Alnico magnetic core of cylindrical configuration. Another guide rod 23 extends from the opposite end of magnetic core 22 along the center axis of the core and the valve member and into a guide opening in a guide collar 24 fixed in the lower region of the housing tube 11 near the lower end 11a thereof.

It will be noted that the valve retainer 20 is slotted as indicated at 200 in FIG. 4, and the guide collar 24 has a series of circumferentially spaced apertures 24a spaced outwardly from the center guide aperture 24b thereof, the slots and the apertures being provided to permit free passage of fluid which is allowed to enter the head portion 14 through the slots 14a and pass through the opening of the valve seat 16 and through the lower section of the housing tube 11.

Mounted on the external surface of the housing tube 11, near the lower end 11a thereof and adjacent the lower end of the head portion 14, are a pair of upper and lower inflatable retention collars 2S and 26 interconnected by one or more interconnecting inflation tubes 27 extending between the collars 25 and 26. The interconnecting tubes 27, shown here as a pair of tubes located at diametrically opposite parts of housing tube 11, form a unitary inflation chamber with the interior chamber portions of the collars 25 and 26 to facilitate inflation of both collars upon inflating of the lower collar 26. It is intended that the inflation chamber portions defined by the collars 25 and 26 and the inflation tubes 27 be inflated with some liquid, such as saline solution, or other desired solution, to which may be added, if desired, anitbiotics to retard possible infection and possibly desensitising drugs. The inflatable collars should be constructed of self-sealing material forming a semipermeable membrane through which the osmotic pro cess might function to permit the collar fluids to leak at a very slow rate and thereby permit any drug used in the solution to accomplish the desired physiological effeet.

The inflatable collars 25, 26 are spaced apart an appropriate distance so that the upper collar, upon inflation, will be disposed at the site where the urethra enters the bladder and thus form a restraining collar against the bladder wall or the top of the prostate gland. while the lower collar 26 is located at the position where the urethra leaves the prostate. gland. Upon implanting of the urethra valve and inflation of the collars 25 and 26, the inflatable collars thus form enlarged rings or restraining collars at the approximate positions illustrated in FIGS. 7 and 8 where the urethra-emerges from opposite portions of the prostate gland, to hold the valve in desired position in the urethra with the head portion 14 disposed within the bladder. In the drawings, the bladder is indicated by the reference character 28 and the prostate gland by the reference character 29. It will be noted from FIG. 7 that a slight curvature is imparted to the body portion 13 of the urethra valve 10, which is permitted by reason of the slightly flexibly deformable character of the plastic material forming the cylindrical housing 11 and valve member, or by preforming of the valve housing and valve member to this configuration.

The urethra valve 10 is conveniently inserted into the urethra and advanced to the appropriate site by a suit able insertion and removing instrument, indicated generally by the reference character 30 in FIG. 6 and shown in decoupled, contracted condition in FIG. 6A. This insertion and removing instrument 30 has an elongated cylindrical instrument tube or body 31 terminating at its forward end in a tapered leading end portion 32 of truncated conical configuration having a conical expansion collet or chuck 33 at the leading end thereof. The collet or chuck 33 is formed of a plurality of split segments 33a which, when contracted into tightly nested condition, define a conical surface which is an extension of the truncated conical surface of the end portion 32. The segments 33a of the expansion collet or expanding chuck are spring biased to the outwardly extended position illustrated in FIG. 6 by means of the spring wires 34 which support the chuck segments 33,

the spring wires 34 and chuck segments 33a being contractable to the closed position illustrated in FIG. 6A by forward movement of the contracting ring 35 surrounding the spring wires 34 and coupled by connecting rod 36 to the activator or plunger 37 at the outer end of the insertion and removing instrument 30.

When the plunger 37 and the ring 35 connected thereto is moved to its forwardmost position, the spring wires 34 are contracted toward each other by the ring 35 from their normal diverging positions, disposing the chuck segments 33a in the nested conical position illustrated in FIG. 6A. When the plunger 37 of the instrument 30 is retracted to its outermost position, the ring 35 occupies the position illustrated in FIG. 6, allowing the spring wires 34 to resiliently move the chuck setments 33a radially outwardly from the axis of the instrument 30 to engage the shoulder on the segments against the annular restraining shoulder of the ring 140, thereby coupling the valve 10 to the insertion and removing instrument 30. The insertion and removing instrument 30 also preferably contains a guide sleeve 38 extending along the length thereof fixed to the external surface of the cylindrical body 31 through which a flexible syringe needle 39 may be inserted to puncture the lower retention collar 26. A tubular conduit 38a, such as plastic tubing, connects the syringe needle 39 to a supply container, such as a collapsible syringe 38b, filled with saline solution or any other antibiotic solution to inflate the collars 25, 26.

With the collars 25, 26 in deflated condition, the complete urethra magnetic valve 10 may be implanted in the urethra by locking the valve unit to the insertion and removing instrument 30 through use of the expanding chuck segments 33a inserted into the throat portion 13b of the coupling ring 13a to interlock with the restraining shoulder 130. The valve unit 10 is then inserted in the urethra and advanced by the insertion and removing instrument 30 to the proper position in the zone of the prostate gland 29, whereupon the flexiole syringe needle 39 is inserted through the guide sleeve 38 to puncture the lower retention collar 26 and inflate the two interconnected retention collars 25 and 26 with the fluid in the syringe 38b. The needle 39 is then withdrawn from the guide sleeve and the plunger or actuator 37 of the instrument 30 pushed inwardly, advancing the contracting ring 35 along the spring wires 34 to cause the chuck to collapse to the condition illustrated in FIG. 6A, so that the insertion tool can be withdrawn from interlocking relation with the ring 13a to leave the valve in the urethra as a temporary implant.

The valve seat member 16, in one preferred embodiment, may be a teflon valve seat designed to accommodate the valve member 15, either of spherical ball shape or of conical shape, with the opening 16a in the valve seat sized so that when the valve is activated and the urine begins to flow, the increased surface of the exposed valve member should permit hydrostatic pressure to assist in keeping the valve open. The design and the tension on the spring 17 should be of such nature so that under normally full bladder pressure, the valve will weep sufficiently to warn the patient that he has exceeded the normal void time, for example if the patient is a paraplegic.

The valve is designed to be controlled by the patient to open the valve and achieve voiding, by the use of an external electromagnetic device creating a magnetic force field of sufficient strength to penetrate the distance between the valve and the external surface back of the scrotum. Examples of such magnetic activating devices are illustrated in FIGS. 7 and 8 and indicated generally by the reference characters 40 and 41. The magnetic activating devices 40 and 41 each include a magnetic head 42 formed for example of a metallic core 43 of any desired configuration and windings indicated generally at 44 creating a force field of sufficient strength to attract the magnetic core member 22 of the valve structure and cause the valve member to be drawn open to permit the fluid to flow freely from the bladder. Power for the windings of the magnetic head can be a standard DC battery or array of batteries, or a small step-down transformer operating off of a standard 110 volt 60 cycle supply and having a full wave DC rectifying bridge formed of diodes to produce the supply current of proper voltage, for example about 15 volts, across the windings of the magnetic head. In the form illustrated in FIG. 7, the external electromagnetic device 40 is shown to have an elongated curved handle portion 45 shaped to extend forwardly around the scrotum from the electromagnetic head to a convenient access position and having, for example, a pushbutton switch 46 thereon to be operated by the thumb of the patient. In the form shown in FIG. 8, the external electromagnetic device 41 has a curved portion 47 projecting forwardly from the head 42 to extend around the scrotum and terminates in a C-shaped clamp portion 48 adapted to releasibly clamp about the neck of a bottle or receptacle 49 to collect the fluid voided from the bladder upon electromagnetic activation of the valve to withdraw the valve member 15 to open position.

A modified form of the implantable device of the present invention is illustrated in FIG. 10, indicated by reference character 10, formed of an elongated generally cylindrical housing tube 11, head portion 12' and a pair of retention collars 25 26. The components of this embodiment corresponding to parts of the firstdescribed embodiment are indicated by reference characters which are primes of the reference characters used in describing the first embodiment. One orboth of the collars 25, 26 in this second embodiment are formed of highly resilient soft rubber or plastic material whose elastic memory normally urges them to the relatively radially enlarged annular configuration shown. The collars 25', 26 are deformed inwardly by unyielding wall regions of the urethra during insertion, to approach substantially conformation to the cylindrical configuration and diameter of the exterior surface of the housing tube 11', but spring back to their enlarged condition when they reach the implant site astride the prostate gland. In this way, the need for the inflation tube 27 and for inflating means is eliminated. Also, need for the spring 17 is eliminated by making the valve seat 16' of magnetic material magnetized to produce a North or South magnetic pole adjacent the ball valve 15', and the ball valve 15 is made of magnetic material of opposite polarity to be permanently attracted to the valve seat. The valve is opened by the magnetic activator device 40 or 41 creating a force field of sufficient strength to move the magnet core 22', and the valve 15 connected thereto, with such force as to overcome the attractive force of the valve seat 16' and retract the valve member 15 to open position. When the field of the activator device 40 or 41 collapses upon deenergization of its electro-magnet, the ball valve member 15' is again attracted magnetically to closed position against the valve seat 16.

The implant valve assembly 10 or 10' need not be especially formed to be coupled to the insertion and removing instrument 30, but may be inserted in the urethra by other known urethra examination devices, such as the telescoping tubes of known urethrascopes.

What is claimed is:

1. A valve unit to be implanted in the urethra of a patient at the juncture of the urethra with the bladder to be operated by a magnetic force field generated by an external electromagnetic device for controlling the flow of urine through the urethra, the valve comprising an axially elongated hollow tubular housing of substantially cylindrical configuration having an upper spherical end and a lower open end, a valve assembly in the intermediate region of said housing including a centrally apertured annular valve seat member, a movable valve member below said valve seat member normally urged toward said valve seat member to closed position, a magnetic core member connected to said valve member and guided for movement in said housing to retract the valve member to open position responsive to a magnetic force field generated externally of the patients body, and a pair of radially inwardly deformable annular collars located on the exterior surface of said housing at axially spaced locations to assume relatively enlarged condition upon implanting of the valve unit in the urethra and provide retaining collars at the opposite ends of the urethra portion passing through the prostate gland to restrain the valve unit in implanted position, and the portion of said housing above the uppermost collar, defining a head portion having openings for passage of urine from the bladder into the interior of the housing, and a coupling ring at the lower end of said housing having an upwardly converging throat adjoining an upwardly facing annular restraining shoulder for removable coupling of an insertion and removing instrument therewith.

2. A valve unit as defined in claim 1, said collars being normally collapsed inflatable collars which are inflated after insertion to assume such relatively enlarged condition.

3. A valve unit as defined in claim 2, including conduit means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being selfsealing and being puncturable by a syringe needle for inflating and deflating the same.

4. A valve unit as defined in claim 1, including a centrally apertured valve retainer member below said valve seat member having openings for passage of urine therethrough when the valve is in open position, said movable valve member being located between said valve seat member and said valve retainer member.

5. A valve unit as defined in claim 4, wherein said collars are normally collapsed inflatable collars, and conduit means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being self-sealing and being puncturable by a syringe needle for inflating and deflating the same.

6. A valve unit as defined in claim including tension spring means coupled at one end thereof through the aperture in said valve seat member to said valve member and adjustably fastened at its other end to said housing for adjustment of the spring tension force tending to close said valve member against said valve seat member prior to implanting of the valve unit in the urethra.

7. A valve unit to be implanted in the urethra of a patient at the juncture of the urethra with the bladder to be operated by a magnetic force field generated by an external electromagnetic device for controlling the flow of urine through the urethra, the valve comprising an axially elongated hollow tubular housing of substantially cylindrical configuration having an upper spherical end and a lower open end, a valve assembly in the intermediate region of said housing including a centrally apertured annular valve seat member, a movable valve member below said valve seat member normally urged toward said valve seat member to closed position, a magnetic core member connected to said valve member and guided for movement in said housing to retract the valve member to open position responsive to a magnetic force field generated externally of the patients body, and a pair of radially inwardly deformable annular collars located on the exterior surface of said housing at axially spaced locations to assume relatively enlarged condition upon implanting of the valve unit in the urethra and provide retaining collars at the opposite ends of the urethra portion passing through the prostate gland to restrain the valve unit in implanted position, and the portion of said housing above the uppermost collar defining a head portion having openings for passage of urine from the bladder into the interior of said housing, a coupling ring at the lower end of said housing having an upwardly converging throat adjoining an upwardly facing annular restraining shoulder for removable coupling of an insertion and removing instrument therewith, an insertion and removing instrument including an elongated instrument tube having a convergently tapering leading end of truncated conical configuration, an expandable chuck at said leading end releasably coupled to said coupling ring and defining a cone which is an extension of said tapering leading end when in contracted condition and which is made up of conic segments which are radially outwardly movable to expanded position in said valve housing interlocking against said annular restraining shoulder of said coupling ring, spring wires in said instrument tube supporting said conic segments and normally urging them to said expanded position, and a contracting ring in said instrument tube surrounding said wires and mounted for reciprocation axially of the tube by a plunger to expand and contract the conic segments.

8. A valve unit as defined in claim 7, wherein said collars are normally collapsed inflatable collars which are inflated after insertion to assume such relatively enlarged condition.

9. A valve unit as defined in claim 8, including conduit means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being selfsealing and being puncturable by a syringe needle for inflating and deflating the same.

10. A valve unit as defined in claim 7, wherein said collars are formed of resiliently deformable material normally elastically urged to selected radially enlarged annular formations and resiliently contractible to approximately flat condition adjacent the surface of said tubular housing.

11. A valve unit as defined in claim 7, including a centrally apertured valve retainer member below said valve seat member having openings for passage of uring therethrough when the valve is in open position, said movable valve member being located between said valve seat member and said valve retainer member.

12. A valve unit as defined in claim 11, wherein said collars are normally collapsed inflatable collars, conduit means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being selfsealing and being puncturable by a syringe needle for inflating and deflating the same, and tension spring means coupled at one end of the valve unit through the aperture in said valve seat member to said valve member and adjustably fastened at its other end to said housing for adjustment of the spring tension force tending to close said valve member against said valve seat member prior to implanting of the valve unit in the urethra. 

1. A valve unit to be implanted in the urethra of a patient at the juncture of the urethra with the bladder to be operated by a magnetic force field generated by an external electromagnetic device for controlling the flow of urine through the urethra, the valve comprising an axially elongated hollow tubular housing of substantially cylindrical configuration having an upper spherical end and a lower open end, a valve assembly in the intermediate region of said housing including a centrally apertured annular valve seat member, a movable valve member below said valve seat member normally urged toward said valve seat member to closed position, a magnetic core member connected to said valve member and guided for movement in said housing to retract the valve member to open position responsive to a magnetic force field generated externally of the patient''s body, and a pair of radially inwardly deformable annular collars located on the exterior surface of said housing at axially spaced locations to assume relatively enlarged condition upon implanting of the valve unit in the urethra and provide retaining collars at the opposite ends of the urethra portion passing through the prostate gland to restrain the valve unit in implanted position, and the portion of said housing above the uppermost collar, defining a head portion having openings for passage of urine from the bladder into the interior of the housing, and a coupling ring at the lower end of said housing having an upwardly converging throat adjoining an upwardly facing annular restraining shoulder for removable coupling of an insertion and removing instrument therewith.
 2. A valve unit as defined in claim 1, said collars being normally collapsed inflatable collars which are inflated after insertion to assume such relatively enlarged condition.
 3. A valve unit as defined in claim 2, including conduit means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being self-sealing and being puncturable by a syringe needle for inflating and deflating the same.
 4. A valve unit as defined in claim 1, including a centrally apertured valve retainer member below said valve seat member having openings for passage of urine therethrough when the valve is in open position, said movable valve member being located between said valve seat member and said valve retainer member.
 5. A valve unit as defined in claim 4, wherein said collars are normally collapsed inflatable collars, and conduit means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being self-sealing and being puncturable by a syringe needle for inflating and deflating the same.
 6. A valve unit as defined in claim 5 including tension spring means coupled at one end Thereof through the aperture in said valve seat member to said valve member and adjustably fastened at its other end to said housing for adjustment of the spring tension force tending to close said valve member against said valve seat member prior to implanting of the valve unit in the urethra.
 7. A valve unit to be implanted in the urethra of a patient at the juncture of the urethra with the bladder to be operated by a magnetic force field generated by an external electromagnetic device for controlling the flow of urine through the urethra, the valve comprising an axially elongated hollow tubular housing of substantially cylindrical configuration having an upper spherical end and a lower open end, a valve assembly in the intermediate region of said housing including a centrally apertured annular valve seat member, a movable valve member below said valve seat member normally urged toward said valve seat member to closed position, a magnetic core member connected to said valve member and guided for movement in said housing to retract the valve member to open position responsive to a magnetic force field generated externally of the patient''s body, and a pair of radially inwardly deformable annular collars located on the exterior surface of said housing at axially spaced locations to assume relatively enlarged condition upon implanting of the valve unit in the urethra and provide retaining collars at the opposite ends of the urethra portion passing through the prostate gland to restrain the valve unit in implanted position, and the portion of said housing above the uppermost collar defining a head portion having openings for passage of urine from the bladder into the interior of said housing, a coupling ring at the lower end of said housing having an upwardly converging throat adjoining an upwardly facing annular restraining shoulder for removable coupling of an insertion and removing instrument therewith, an insertion and removing instrument including an elongated instrument tube having a convergently tapering leading end of truncated conical configuration, an expandable chuck at said leading end releasably coupled to said coupling ring and defining a cone which is an extension of said tapering leading end when in contracted condition and which is made up of conic segments which are radially outwardly movable to expanded position in said valve housing interlocking against said annular restraining shoulder of said coupling ring, spring wires in said instrument tube supporting said conic segments and normally urging them to said expanded position, and a contracting ring in said instrument tube surrounding said wires and mounted for reciprocation axially of the tube by a plunger to expand and contract the conic segments.
 8. A valve unit as defined in claim 7, wherein said collars are normally collapsed inflatable collars which are inflated after insertion to assume such relatively enlarged condition.
 9. A valve unit as defined in claim 8, including conduit means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being self-sealing and being puncturable by a syringe needle for inflating and deflating the same.
 10. A valve unit as defined in claim 7, wherein said collars are formed of resiliently deformable material normally elastically urged to selected radially enlarged annular formations and resiliently contractible to approximately flat condition adjacent the surface of said tubular housing.
 11. A valve unit as defined in claim 7, including a centrally apertured valve retainer member below said valve seat member having openings for passage of uring therethrough when the valve is in open position, said movable valve member being located between said valve seat member and said valve retainer member.
 12. A valve unit as defined in claim 11, wherein said collars are normally collapsed inflatable collars, conduiT means interconnecting said pair of inflatable collars whereby inflating fluid may be introduced into and withdrawn from the lowermost collar for inflating or deflating both collars, said lowermost collar being self-sealing and being puncturable by a syringe needle for inflating and deflating the same, and tension spring means coupled at one end of the valve unit through the aperture in said valve seat member to said valve member and adjustably fastened at its other end to said housing for adjustment of the spring tension force tending to close said valve member against said valve seat member prior to implanting of the valve unit in the urethra. 